The balloon will get bigger if you increase temperature while keeping pressure and number of moles constant.
According to Charles' Law, when pressure and number of moles are kept constant, the volume an ideal gas occupies is directly proportional to its temperature.
The higher the temperature, the bigger the volume. Likewise, the lower the temperature, the smaller the volume.
Mathematically, this is written as
According to the above equation, the volume of the balloon will be